1. Field of the Invention
The present invention relates to a display device including a self-luminous photo-emission element such as an organic EL (electroluminescence) element.
2. Description of the Related Art
In a display device, a viewing angle characteristic of luminance is a factor causing a remarkable reduction in a display quality. Typically, in a self-luminous photo-emission element (self-luminous element) such as an organic EL element, an element is configured so as to improve extraction efficiency from the front direction, by utilizing perfect diffusion, the microcavity efficiency of a resonator structure, or the like. That is, since a photo-emission section is designed to be disposed close to a perfect-diffusion light source, it is said that the photo-emission itself is advantageous in terms of the viewing angle characteristic of the luminance
However, in the case where the display device is configured by using such a self-luminous element, to realize a high contrast, there is a case where a black matrix layer is provided for the purpose of suppressing reflection of natural light from a backplane (in a pair of substrates, the substrate on a side opposite from a display plane). Moreover, to improve color purity in addition to the high contrast, there is a case where the black matrix layer which is integrated with a color filter is provided.
Here, in a self-luminous display device of the related art in which such a black matrix layer is provided, the black matrix layer is disposed on the substrate facing the backplane, in the pair of substrates. This is because, although heat-resistance and reliability in the photo-emission element are demanded when forming the black matrix layer on the backplane, it is difficult to find such a material at the present moment. Thus, it is substantially necessary to form the black matrix layer on the facing substrate side.
Therefore, when the backplane, and the facing substrate in which the black matrix layer is formed are aligned and bonded to each other, there is a gap formed by the thickness of an adhesion layer (sealing layer) for bonding, and a protective layer, between the photo-emission section and the black matrix layer. Typically, the distance between the photo-emission section and the black matrix layer, including the adhesion layer and the protective layer, is approximately 30 μm.
As an example of the self-luminous display device including such a self-luminous photo-emission layer, there is an organic EL display device (for example, Japanese Unexamined Patent Publication No. 2006-73219).